Cassettes containing a spool of ribbon in which during use, the ribbon is transferred to another spool, are known. They are employed in tape recoders, typewriters, printers and so on to carry items such as magnetic tape or inked ribbon. These cassettes usually have features, such as sprocketed holes in the centre of one or both of the spools, which allow the apparatus on which the cassette is to be used, to transmit a driving force to the cassette which will wind the used ribbon onto the take-up spool.
The mechanisms used in such arrangements are complex and a motor or other prime mover is required to power the drive mechanism. This prime mover may be synchronised with the take-up spool speed requirements or, as is more often the case, a slipping clutch is used to automatically control the speed of take-up. In addition, the cassette must be designed so that the drive mechanism will readily engage the cassette. This is usually simplified by allowing the spools to `float` within the cassette. The spools can then align themselves with the drive mechanism as the cassette is inserted.
A still more complex arrangement is necessary if the cassette is to be inserted into the apparatus in a direction other than parallel to the axes of rotation of the spools. It may then be necessary to use an arrangement in which the drive mechanism is moved into engagement with the cassette spools after the cassette has been fully inserted.